基于暂态电压的多端柔性直流线路保护方案  

Protection scheme for multi-terminal VSC-HVDC lines based on transient voltage

作　　者：嵇康[1] 邰能灵[1] 刘剑[1] 王彦虹 JI Kang;TAI Neng-ling;LIU Jian;WANG Yan-hong(School of Electronic Information and Electrical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学电子信息与电气工程学院,上海200240

出　　处：《电力科学与技术学报》2018年第1期3-10,共8页Journal of Electric Power Science And Technology

基　　金：国家自然科学基金(51377104)

摘　　要：多端柔性直流线路故障电流具有上升速度快、峰值大的特点。为了限制故障电流,通常会在直流断路器中串联限流电抗器,形成直流线路的天然边界,但这也导致了故障电压暂态过程变化。区内故障时,线路两端保护安装处的暂态电压高频分量的有效值均大于限流电抗器换流站侧的值;区外故障时,故障端的特性与之相反。基于上述故障特征,提出一种基于暂态电压的多端柔性直流系统保护方案,利用单端线路侧的电压微分率实现区、内外故障快速动作,利用线路双端限流电抗器两侧暂态电压比实现区内、外故障的可靠判别。算例仿真结果表明:所提保护方案动作速度快,受过渡电阻影响小,且线路两端无需数据同步。The fault current of the multi-terminal VSC-HVDC has the characteristics of high rising rate and large peak value.In order to limit the fault current,the current-limiting reactor is often connected in series in a DC circuit breaker.It forms the natural boundary of DC lines,but it also leads the voltage transient process change.For an internal fault,the amplitude of high-frequency transient voltage at line side is higher than that at station side,while the fault characteristics is opposite under external fault.Based on the transient voltage features,a protection scheme for multi-terminal VSC-HVDC lines was proposed in this paper.The fast action of internal fault metallicity fault was realized by distinguishing voltage derivative rate of single-ended line side.And by the current-limiting reactor transient voltage ratio of each line terminal,the fault would be reliably discriminated whether it is internal or external.The simulation results show that the proposed protection scheme is speedy,and not influenced by fault resistance.And it does not need the data synchronization between two terminal.

关 键 词：多端柔性直流 暂态电压 纵联保护 电压微分率 

分 类 号：TM773[电气工程—电力系统及自动化]